1. Field of the Invention
The present invention relates to an image display device and, more particularly, to an image display device called flat panel display of selfluminous type with an array of thin-film electron sources.
2. Description of the Related Art
The thin-film electron source is basically composed of three thin films functioning as upper electrode, electron accelerating layer, and lower electrode, which are placed one over another. It emits electrons into a vacuum from the surface of the upper electrode upon application of a voltage across the upper electrode and the lower electrode.
The thin film electron source includes the following three types and others.
Metal-insulator-metal (MIM) type, composed of metal layer, insulator layer, and metal layer which are placed one over another.
Metal-insulator-semiconductor (MIS) type, composed of metal layer, insulator layer, and semiconductor layer which are placed one over another.
Metal-insulator-semiconductor-metal type, composed of metal layer, insulator layer, semiconductor layer, and metal layer which are placed one over another.
Their references are listed below.
Patent documents 1, 2, and 3 concerning the MIM type.
Non-patent document 1 concerning MIS type (for MOS).
Non-patent document 2 concerning metal-insulator-semiconductor-metal type (for HEED).
Non-patent document 3 concerning EL type.
Non-patent document 4 concerning porous-silicon type.
Patent document 1: Japanese Patent Laid-open No. Hei-7-56710
[Non-patent document 1] K. Yokoo, et al., “Emission characteristics of metal-oxide-semiconductor electron tunneling cathode,” J. Vac, Sci. Technol., B11(2), pp. 429-432 (1993)
[Non-patent document 2] N. Negishi, et al., “High Efficiency Electron-Emission in Pt/SiOx/Si/Al Structure,” Jpn. J. Appl. Phys., vol 36, Part 2, No. 7B, pp. L939-L941 (1997)
[Non-patent document 3] S. Okamoto, “Electron emission from electroluminescent thin film—thin film cold electron emitter—” (in Japanese), OYO BUTURI (Applied Physics), vol. 63, No. 6, pages 592-595 (1994)
[Non-patent document 4] N. Koshida, “Light emission from porous silicon—Beyond the indirect/direct transition regime—,” (in Japanese), OYO BUTURI (Applied Physics), vol. 66, No. 5, pages 437-443 (1997)